71 - Primary Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is one of an expanding collection of disorders collectively known as ciliopathies. A rare, inherited disease of the motile cilia, PCD is clinically characterized by chronic upper and lower airway disease, left-right laterality defects, and infertility caused by ciliary (or flagellar) dysfunction. For four decades, the diagnosis of PCD has been based on the presence of ultrastructural defects in the ciliary axoneme using transmission electron microscopy analysis, but newer diagnostic tests have recently emerged, including nasal nitric oxide measurement, high-speed videomicroscopy with ciliary beat pattern analysis, and immunofluorescence imaging for specific axonemal proteins. Genetic testing has also become an increasingly useful diagnostic alternative. Indeed, a growing number of PCD-associated genes have been identified, which encode proteins essential for ciliary assembly, structure, and function, which has advanced our understanding of the disease. In this chapter, we will review the genetics and pathophysiology of PCD, describe emerging diagnostic tests, and outline current therapies for this rare lung disease.